Botulinum Toxin for Strabismus Treatment

NCT07180394 | Not Yet Recruiting DMC

• 2 other identifiers: FUMCRCT21004/RC/FFH/RWP
• Study Type: interventional
• Target: 127
• Locations: 1 country
• Sites: 1

Brief Summary

The bacterial species Clostridium botulinum produces a class of neurotoxins known as botulinum toxin. At the neuromuscular junction, botulinum toxin A prevents acetylcholine from being released. Following a Botox intramuscular injection, the injected EOM becomes paralysed 2-4 days after the injection and remains so clinically for at least 5-8 weeks. Muscle function recovery takes five to fourteen weeks, depending on the injection site, volume, and concentration of the solution, as well as the innervation density. Botulinum toxin treatment results in a pharmacologic recession of the injected extraocular muscle, and the muscle lengthens while its agonist contracts, paralysing it. Improved ocular alignment or a decrease in the severity of the deviation may last for a long time, even if the pharmaceutical impact normally goes away after three months. Even after the pharmacologic effect has worn off, a number of elements, such as mechanical, proprioceptive, and binocular effects, may intervene during the period of muscle paralysis to help stabilise and improve alignment in strabismus patients over the long term.

Conditions

Strabismic Deviation; Strabismus

Keywords

Strabismus; esotropia; exotropia; hypotropia; hypertropia; Botulinum toxin; therapy; outcomes

Outcome Measures

Primary Outcomes (1)

• Change in Strabismus Angle in Prism Diopters (PD) in the Primary Position from the baseline angle at Week 2, Week 6, 3 months, 6 months, 9 months, and 1 year of the first intramuscular botox injection.

  Using the prism cover test (PCT), the strabismus angle in the primary position was determined. The mean of the strabismus angle when viewed from a distance of 6 meters and when viewed from a distance of 33 centimetres was used to calculate the strabismus angle. The same afflicted eye (either the left or the right) was used for each participant's examination for the course of the trial. The difference between the values at Week 2, Week 6, 3 months, 6 months, 9 months, and 1 year and baseline, was used to compute the change from Baseline.

  Baseline, at 2 weeks post injection, to 1 year post injection

Study Arms (1)

Botulinum toxin for strabismus treatment

EXPERIMENTAL

The primary objective is to examine the efficacy and outcomes of Botox (botulinum toxin) intramuscular injection therapy in the treatment of pediatric or adult strabismus

Drug: Botox injection into extraocular muscles

Interventions

Botox injection into extraocular muscles DRUG

Botulinum toxin in various doses by injecting it into the overacting extraocular musces in strabismus patients, especially pediatric, but also adult cases, to use it as an alternative for strabismus surgery. For children, it will be administered under sedation or general anesthesia and in adults, under topical anesthesia. The pre-operative measurements of the type of strabismus, patterns, deviation, and post-operative results will be studied both in the short and long-term.

Botulinum toxin for strabismus treatment

Eligibility Criteria

• Age: 1 Month+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Esotropia or exotropia presenting with a small-to-moderate angle deviation (\<40 PD)
• Acute onset comitant esotropia
• Postoperative residual or consecutive strabismus (2-8 weeks postoperatively or later)
• Acute paralytic strabismus to alleviate diplopia while the palsy resolves (mainly sixth nerve palsies, sometimes fourth nerve palsy)
• Active thyroid eye disease (Graves Disease), inflamed or pre-phthisical eyes, when surgery is not recommended
• Adjunct to surgery for large-angle esotropia or sixth nerve palsy or for large-angle exotropia
• As a muscle sparing option in patients at risk of anterior segment ischemia

You may not qualify if:

• Unrealistic expectations
• Neuromuscular disorders: Amyotrophic Lateral Sclerosis (ALS), Myasthenia Gravis and Eaton-Lambert syndrome
• Pregnancy and breastfeeding

Sponsors & Collaborators

• Foundation University Islamabad: lead

Study Sites (1)

Fauji Foundation Hospital, Rawalpindi

Rawalpindi, Punjab Province, 44000, Pakistan

Location

Related Publications (3)

• Badakere A, Badrinath V, Dhillon HK, Valliappan A, Natarajan V, Agarkar S. Botulinum toxin A as a treatment modality for acute acquired comitant esotropia - An Indian perspective. Indian J Ophthalmol. 2025 Feb 1;73(2):228-230. doi: 10.4103/IJO.IJO_2198_23. Epub 2024 Aug 14.

  PMID: 39186638 BACKGROUND

• Scott AB, Fahn S, Brin MF. Treatment of strabismus and blepharospasm with Botox (onabotulinumtoxinA): Development, insights, and impact. Medicine (Baltimore). 2023 Jul 1;102(S1):e32374. doi: 10.1097/MD.0000000000032374.

  PMID: 37499080 BACKGROUND

• Bort-Marti AR, Rowe FJ, Ruiz Sifre L, Ng SM, Bort-Marti S, Ruiz Garcia V. Botulinum toxin for the treatment of strabismus. Cochrane Database Syst Rev. 2023 Mar 14;3(3):CD006499. doi: 10.1002/14651858.CD006499.pub5.

  PMID: 36916692 BACKGROUND

MeSH Terms

Conditions

Strabismus; Esotropia; Exotropia

Condition Hierarchy (Ancestors)

Ocular Motility Disorders; Cranial Nerve Diseases; Nervous System Diseases; Eye Diseases

Study Officials

• Dr. Sana Nadeem Assoc. Prof., FCPS

  Foundation University Islamabad

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Dr. Sana Nadeem Associate Professor of Ophthalmology, FCPS, Fellowship in Ped Oph

CONTACT

+923425402394; sana.nadeem@fui.edu.pk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Public Health Officer

Model Details: The primary objective is to examine the efficacy and outcomes of Botox (botulinum toxin) intramuscular injection therapy in the treatment of pediatric or adult strabismus

Study Record Dates

• First Submitted: August 11, 2025
• First Posted: September 18, 2025
• Study Start: September 30, 2025
• Primary Completion (Estimated): August 30, 2030
• Study Completion (Estimated): August 30, 2030
• Last Updated: September 18, 2025

Record last verified: 2025-09

Locations

PA (1)